BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20251121T162510EST-1552TJdUk3@132.216.98.100 DTSTAMP:20251121T212510Z DESCRIPTION:Title: Perfect bases in representation theory.\n\nAbstract: A f amous foundational problem concerns finding combinatorial expressions for tensor products of irreducible representations. A conceptually satisfying way to answer this question is to find bases for representations which res trict to bases of tensor product multiplicity spaces. These bases are call ed 'good' or 'perfect' and were first proposed 35 years ago by Gelfand and Zelevinsky. The construction of such bases is more difficult than one mig ht expect and cannot be achieved by elementary means: they require geometr ic inputs such as the geometric Satake correspondence (Mirkovic-Vilonen)\, or the theory of perverse sheaves on quiver varieties (Lusztig). These le ad to the MV basis\, and Lusztig's dual canonical and dual semicanonical b ases.\n Remarkably\, each such perfect basis gives rise to the same combina torial structure\, which is encoded as a collection of polytopes. With Pie rre Baumann and Allen Knutson\, we defined measures supported on these pol ytopes. These measures allow us to perform computations which distinguish among these different bases.\n DTSTART:20220331T200000Z DTEND:20220331T210000Z LOCATION:Room 920\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Joel Kamnitzer (University of Toronto) URL:/mathstat/channels/event/joel-kamnitzer-university -toronto-338767 END:VEVENT END:VCALENDAR